The energy efficiency of road refrigerated transport is still a less researched area, despite a significant amount of energy being used for cooling perishable goods inside the refrigerated vehicle. The refrigeration units of these vehicles continuously operate while en route from the cargo sender to the recipient, even during the vehicle’s forced stopovers due to the driver’s working time limitations. This article aims to summarize the impact of the parking sheds used in rest and service areas on the energy consumption of the vehicle’s refrigeration unit. The achievable cost savings by decreasing the energy consumption of the semi-trailer’s refrigeration units are also presented. We establish a mathematical model to calculate the heat balance and verify our approach. The calculation results, which were carried out under certain operating conditions of the refrigeration unit of a semi-trailer, provide an opportunity to achieve savings on a scale of 12.03%. Lastly, ideal locations of rest and service areas with sheds along the motorways and expressways in Poland are also proposed.